San Diego 
District Attorney Bonnie Dumanis and others being sued by a Marine wife who was convicted of killing her husband with arsenic have asked a federal judge to find that they were not negligent in the prosecution, even though evidence revealed later led to the murder case being dismissed.

Cynthia Sommer, who filed the $20 million civil-rights suit, was charged in 2006 with murder for financial gain. A jury convicted her after hearing testimony that she had used Sgt. Todd Sommer’s life insurance money to pay for breast implants, and had partied in San Diego and Tijuana after his death.

Tissues taken from the husband’s body — evidence which was frozen — showed extremely high levels of arsenic in the 23-year-old’s liver and kidneys, and much lower levels in other tissues. It was a key piece of evidence at the trial.

After Cynthia Sommer was convicted and later granted a new trial, a second set of tissue samples — preserved in paraffin — was tested and revealed no arsenic. That prompted the District Attorney’s Office to drop the case, saying the evidence pointed to reasonable doubt.

Sommer, then a 34-year-old mother of four, was freed from county jail, where she had spent nearly 2½ years while the case was pending in San Diego Superior Court.

In 2009, she filed the lawsuit against Dumanis and others, accusing them of violating her civil and constitutional rights.

Sommer accused prosecutors and investigators, including the Naval Criminal Investigative Service, of being grossly negligent when investigating her husband’s death, which led to her arrest, confinement and ongoing damage to her reputation.

Dumanis and the others want the judge to dismiss the lawsuit or remove them from the case because they were not negligent. The others named in the suit are the U.S. government, Chief Medical Examiner Glenn Wagner and Deputy District Attorney Laura Gunn, who prosecuted Sommer.

U.S. District Judge Cathy Ann Bencivengo heard arguments this week on the request and said she would issue a written decision later.

The arguments focused on whether the defendants had shown a “reckless disregard for the truth” before and after Sommer’s case went to trial. The judge’s comments from the bench indicated she was not convinced of any deliberate wrongdoing.

“This whole focus is on the medical testing,” the judge said. “What did the NCIS people do to overlook or deliberately disregard information that would have destroyed their theory of the case? I don’t see it.”

Robert Rosenthal, a Monterey-based lawyer who represents Sommer, argued that NCIS authorities were asked twice early on whether any tissue samples existed other than those that were frozen. The agency said no.

“If NCIS had answered the question, the arrest would not have occurred,” Rosenthal said.

The military doctor who initially performed the autopsy on Todd Sommer determined he had died a natural death from cardiac arrhythmia. Wagner, the chief medical examiner, changed the death certificate in 2005 to say it was a homicide.

Rosenthal argued that Wagner didn’t do enough to investigate whether the high levels of arsenic in some of the tissues were the result of contamination.

Lawyers for the defendants contended that their clients and the agencies they represent acted in good faith when investigating the sudden death of the Miramar-based Marine and the possible link to his wife.

Morris Hill, senior deputy county counsel, outlined several points in the investigation chronologically, arguing that the sequence of events shows that the defendants engaged in a “diligent search for the truth.”

“Ms. Sommer cannot point to a day, an hour or a minute that she was in custody that was not authorized by the court process,” Hill said.

He and Assistant U.S. Attorney Beth Clukey also argued that the tissue samples preserved in paraffin were considered by scientists to be “imperfect.” The best samples were the frozen ones.

They both also said enough evidence was presented at Sommer’s trial to convict her.